The present invention relates to random number generators and, more particularly, to a random number generator for generating true random binary numbers or bits.
Random number generators are useful in data processing equipment in a number of different ways. For example, a random number generator can be used to generate keys for encrypting data transmitted over a transmission line, so that unauthorized tapping of the transmission line will not yield an understandable message.
One problem encountered in the past with random number generators is that it is very difficult to obtain a sequence of true (or nearly true) random numbers. That is, the numbers generated at the output of a random number generator are frequently either (1) biased or (2) auto-correlated. By "biased", it is meant that there is greater than a fifty percent chance that each bit will be only one of the two binary values. By "auto-correlated", it is meant that the generated numbers tend to be periodic or cyclical.
Number generators generating numbers that appear random but that are actually periodic are sometimes referred to as pseudo-random number generators and, in many circumstances, are acceptable. However, in many other circumstances, such as in the generation of keys for data encryption, a non-periodic or "true" random sequence would be preferable.